What is the Megafauna in Australia

Ever wonder why Australian animals are so unique? So different from those found elsewhere in the world? It’s because we’ve been an island (a petri dish, if you will) for the better part of the last 50 million years, and species have been able to evolve in isolation. But where did they first come from?

The oldest native mammals of Australia descended from animals that were on the continent when it separated from Antarctica. As Australia drifted north, other species arrived from Southeast Asia. While bats had the luxury of air travel, the arrival of the dingo potentially coincides with the last great flood, which raised sea levels, and created the separation of previously much closer landmasses around 9,000 years ago. This relatively recent introduction of the dingo had a significant impact on the existing Australian ecosystem, particularly on the mainland.

Marsupial fossils found in Antarctica suggest that the 120 or so varieties currently inhabiting Australia evolved from those early creatures – decidedly bigger creatures at that. Approximately 1.6 million years ago, Megafauna roamed at large and are even thought to have co-existed with humans for at least 30,000 years. This coexistence raises fascinating questions about the interactions between early Australians and these giant beasts, and the potential role humans played in their eventual extinction.

What is a Megafauna

The term “megafauna” refers to a group of large or giant animals. While there isn’t a strict scientific definition based on size, it generally encompasses animals significantly larger than the average size of animals in their respective ecosystems. Think elephants, whales, giraffes – animals that immediately come to mind when you picture “big.” However, the definition of megafauna can be context-dependent. What’s considered “mega” in one environment might be average in another.

Australia’s megafauna, during the Pleistocene epoch (which ended about 11,700 years ago), was truly extraordinary. Imagine a world where giants walked the earth, a stark contrast to the animals we see today. This epoch, often referred to as the Ice Age, saw a fascinating array of megafauna across the globe, and Australia was no exception. Isolated for millions of years, Australia developed a unique and diverse megafauna assemblage, distinct from that found on other continents.

The Australian megafauna of the Pleistocene included a variety of impressive creatures:

The three-ton Diprotodon (a hippopotamus-sized wombat-koala hybrid, thought to have inspired the legend of the Bunyip) is the largest known marsupial ever to have lived. Picture a creature with the size of a hippo and a blend of wombat and koala features – a truly remarkable animal! Closely related was Phascolonus gigas, the giant wombat (weighing in at a hefty 200kg). These giant wombats were much larger than their modern relatives and would have significantly shaped the landscape.

Arguably the strangest-looking megafauna would have been Procoptodon goliah, the ten-foot gorilla-faced kangaroo. Imagine a kangaroo standing over three meters tall with a face reminiscent of a gorilla – a truly bizarre and impressive sight! But Genyornis newtoni, the ostrich-sized, flightless duck, could have given ancient “Skippy” a run for his money. This giant duck, much larger than any duck we see today, would have roamed the wetlands and waterways of ancient Australia.

Reptiles loomed large too. Varanus priscus (formerly known as Megalania prisca), the giant, carnivorous goanna, grew to as long as 7 meters, making it the largest terrestrial lizard ever known. Imagine this massive reptile stalking its prey across the ancient Australian landscape! Quinkana, a terrestrial crocodile, also reached impressive sizes of up to 7m. Unlike modern crocodiles that spend much of their time in water, Quinkana was a land-dwelling predator, adding another layer of danger to the megafauna world. And at 10m long, Liasis dubudingala was the largest Australian snake ever known, a truly gigantic constrictor.

The reasons for the extinction of Australia’s megafauna are still debated by scientists. While climate change and habitat alteration likely played a role, the arrival of humans and their hunting practices are also suspected to have contributed to the decline and eventual disappearance of these magnificent creatures.

While the Megafauna reign has long subsided, when you consider the great white shark (reaching over 6m and 3,000kg), monitor lizards (some more than 2.5m), or the everyday saltwater croc (weighing in at around 770kg) still roaming about, you can’t deny that Australia still boasts some pretty darn mega creatures. These modern giants are a reminder of the incredible diversity and scale of life that has existed, and continues to exist, on this unique continent. What do you think? Are there any other “mega” creatures in Australia that deserve a mention?